Figure 6. IFNγ from either CD4 or CD8 T cells is required for bone marrow failure in IL-2^−/− mice.

Total CD4⁺ and CD8⁺ cell numbers from 19-22 day old mice gated on live cells (A). Representative flow plot of CD44 and CD62L expression gated on BM CD8⁺ cells (B). Total BM LSK HSC, CMP, and MEP cell numbers from indicated mice (C). (D-E) CD4⁺ and CD8⁺ T cells were sorted from 18-21 day old IL-2^−/−IFNγ^WT mice and IL-2^−/−IFNγ^−/− mice. 5×10⁶ FACS sorted CD4⁺ and CD8⁺ cells from the indicated groups were mixed at 1:1 ratio and injected into TCRα^−/− recipient mice. Hematocrit was monitored every other week by obtaining peripheral blood. At 7 weeks, mice were harvested. CBC was determined relative to uninjected TCRα^−/− mice (D). BM was collected and stained for LSK HSCs, CMPs, and MEPs (E). (A-C) Data are from 4 independent experiments; IL-2^WTIFNγ^−/− n=7; IL-2^−/−IFNγ^WT n=8; IL-2^−/−IFNγ^−/− n=8. (DE) Data are from 3 independent experiments with n=6-10 mice per group. n.s. - not significant; * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001 based on students t test.